Steering device

ABSTRACT

A steering device is configured such that an EA stopper and a telescopic lock tooth are engaged with each other such that an inner column and a fixation member move forward with respect to a hanger bracket in a case where a load in a forward direction that acts on the inner column is equal to or greater than a predetermined value. Regarding a telescopic stopper, the fixation member comes into contact with the telescopic stopper in accordance with movement of the inner column and the fixation member with respect to the hanger bracket such that the telescopic stopper rotates in a withdrawal direction in which the telescopic stopper is withdrawn from the fixation member.

CROSS-REFERENCE TO RELATED APPLICATION

Priority is claimed on Japanese Patent Application No. 2017-221854,filed on Nov. 17, 2017, the contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a steering device.

Description of Related Art

There is a steering device that has a telescopic function. Thetelescopic function is a function of adjusting the position of asteering wheel in a front-rear direction according to the physique ordriving posture of a driver. Such a steering device is provided with anouter column and an inner column. The inner column is inserted into theouter column such that the inner column can be moved with respect to theouter column. The inner column rotatably supports a steering shaft towhich the steering wheel is attached.

In the above-described steering device, a configuration for alleviatingan impact load, which is applied to a driver during a process in whichthe inner column is moved forward with respect to the outer column in acase where a predetermined load acts on the steering wheel at the timeof secondary collision, is installed.

For example, in Japanese Unexamined Patent Application, FirstPublication No. 2016-185756 (hereinafter, referred to as Patent Document1), a stopper formed on an outer circumferential surface of an innercolumn is inserted into a telescopic elongated hole formed in the outercolumn.

According to this configuration, at the time of a telescopic stroke, thestopper moves in the front-rear direction inside the telescopicelongated hole in accordance with movement of the inner column withrespect to the outer column. Meanwhile, at the time of a collapse strokein the secondary collision, the stopper is broken after bumping againsta front end opening edge of the telescopic elongated hole during aprocess in which the inner column is moved forward with respect to theouter column. Thereafter, when the inner column moves forward, impactabsorbing means bends and deforms an energy absorbing member, which isprovided between a lock plate held at a random position and the innercolumn, in a crumpling manner such that an impact load can be absorbed.

However, the above-described configuration in Patent Document 1 stillhas room for improvement in a point of achieving improvement in impactabsorbing performance while achieving reduction in size of the steeringdevice in the front-rear direction.

That is, in the case of the above-described configuration in PatentDocument 1, at the time of the collapse stroke, the stopper and thefront end opening edge of the telescopic elongated hole bump againsteach other and a load (bumping load) that causes the stopper to bebroken is generated. Therefore, the variation in load at the time of thecollapse stroke is great.

Therefore, an aspect of the present invention provides a steering devicewith which it is possible to suppress a variation in load at the time ofa collapse stroke and to achieve a stable impact absorption load.

SUMMARY OF THE INVENTION

In order to solve the aforementioned problems, the present inventionadopts the following aspects.

(1) A steering device according to an aspect of the invention includesan outer column that extends in a front-rear direction and is formedwith a slit extending in the front-rear direction, an inner column thatis inserted into the outer column such that the inner column moves inthe front-rear direction and into which a steering shaft is insertedsuch that the steering shaft rotates around a first axis extending inthe front-rear direction, a switching unit that is provided with a lockbolt rotating around a second axis extending in a lateral direction andthat is configured to switch between a locked state, in which the innercolumn is restricted from moving with respect to the outer column, andan unlocked state, in which the inner column is allowed to move withrespect to the outer column, by expanding or contracting the slit, atelescopic restricting portion provided for the inner column, and atelescopic stopper that is engaged with the telescopic restrictingportion when the inner column moves in the front-rear direction withrespect to the outer column in the unlocked state such the inner columnis restricted from moving in the front-rear direction with respect tothe outer column. A holder that is configured to rotate around thesecond axis in accordance with rotation of the lock bolt is connected tothe lock bolt. The telescopic stopper is held by the holder to besupported by the lock bolt such that the telescopic stopper rotatesaround the second axis. In a case where a load in a forward directionthat acts on the inner column is equal to or greater than apredetermined value in the locked state, the telescopic restrictingportion and the telescopic stopper come into contact with each othersuch that the telescopic stopper rotates in a withdrawal direction inwhich the telescopic stopper is withdrawn from the telescopicrestricting portion.

In the case of the steering device according to the aspect, when thetelescopic restricting portion and the telescopic stopper come intocontact with each other at the time of a collapse stroke, the telescopicstopper rotates in the withdrawal direction in which the telescopicstopper is withdrawn from the telescopic restricting portion. Therefore,it is possible to suppress a bumping load that is generated due tocontact between the telescopic restricting portion and the telescopicstopper and to alleviate a variation in load at the time of the collapsestroke. Accordingly, it is possible to efficiently alleviate an impactload over the entire collapse stroke and thus it is possible to achievean improvement in impact absorbing performance.

(2) In the steering device according to (1), an outer circumferentialsurface of the lock bolt is preferably formed with a bolt engagementportion, the holder is preferably provided with a holder insertion holethat is engaged with the bolt engagement portion, and the telescopicstopper is preferably provided with a telescopic insertion hole of whicha diameter is larger than a maximum outer diameter of the boltengagement portion.

According to the aspect, the holder that is provided with the holderinsertion hole that is engaged with the bolt engagement portion supportsthe telescopic stopper. With regard to this, the telescopic insertionhole of the telescopic stopper is formed to have the diameter largerthan the maximum outer diameter of the bolt engagement portion.Therefore, the telescopic stopper can rotate in accordance with rotationof the lock bolt at the time of a telescopic motion. The telescopicstopper can rotate in the withdrawal direction by coming into contactwith the telescopic restricting portion at the time of the collapsestroke.

(3) In the steering device according to (1) or (2), the holder ispreferably configured to be deformed with the telescopic stopperrotating in the withdrawal direction.

According to the aspect, the telescopic stopper can smoothly rotate inthe withdrawal direction. It is possible to suppress a load at which thetelescopic stopper and the telescopic restricting portion abut onto eachother and to suppress a variation in load at the time of the collapsestroke. Accordingly, an impact absorption load becomes stable and it ispossible to achieve an improvement in impact absorbing performance.

(4) The steering device according to any one of (1) to (3) preferablyfurther includes an EA stopper that is connected to the lock bolt androtates around the second axis in accordance with rotation of the lockbolt and a hanger bracket that is provided with a telescopic engagementportion with which the EA stopper is engaged in accordance with rotationof the lock bolt and that is attached to the inner column via a fixationmember. The hanger bracket and the fixation member preferably constitutethe telescopic restricting portion. In a case where a load in theforward direction that acts on the inner column is equal to or greaterthan a predetermined value in the locked state, the EA stopper and thetelescopic engagement portion are preferably engaged with each othersuch that inner column and the fixation member move forward with respectto the hanger bracket. At least a portion of the hanger bracket in thefront-rear direction that overlaps the telescopic engagement portion ispreferably formed with a guide hole that extends in the front-reardirection and guides movement of the fixation member with respect to thehanger bracket. The fixation member preferably comes into contact withthe telescopic stopper in accordance with the movement of the innercolumn and the fixation member with respect to the hanger bracket.

According to the aspect, the telescopic engagement portion (telescopicstroke region) and the guide hole (collapse stroke region) overlap eachother in the front-rear direction. Therefore, it is possible to reducethe length of a steering column in the front-rear direction incomparison with a case where the telescopic stroke region and thecollapse stroke region are arranged in the front-rear direction.Accordingly, it is possible to achieve reduction in size of a columnunit in the front-rear direction. In addition, it is possible to securea sufficient collapse stroke region even in a case where the length ofthe steering column in the front-rear direction is short.

(5) In the steering device according to (4), the fixation member and thetelescopic stopper preferably abut onto each other in a directionintersecting the front-rear direction in the unlocked state such thatthe inner column is restricted from moving forward.

According to the aspect, at the time of the telescopic motion, thetelescopic stopper and the telescopic restricting portion abut onto eachother in a direction intersecting the front-rear direction such that aload that acts between the telescopic stopper and the telescopicrestricting portion in a normal direction of a contact surface betweenthe telescopic stopper and the telescopic restricting portion isdecomposed into a load in a forward direction and a load in a verticaldirection. That is, a component of the load that acts between telescopicstopper and the telescopic restricting portion at the time of thetelescopic motion can be caused to act in a direction that is differentfrom a direction in which the telescopic stopper is rotated such thatthe locked state is entered (forward direction). Therefore, it ispossible to reliably restrict the inner column from moving forward withrespect to the outer column while suppressing unexpected rotation of thetelescopic stopper.

According to the aspects, it is possible to suppress a variation in loadat the time of a collapse stroke and to achieve a stable impactabsorption load.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a steering device.

FIG. 2 is a sectional view taken along line II-II in FIG. 1.

FIG. 3 is a sectional view taken along line III-III in FIG. 1.

FIG. 4 is a bottom view of the steering device.

FIG. 5 is an enlarged perspective view of a hanger bracket and a lockmechanism.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 5.

FIG. 7 is an exploded perspective view of the lock mechanism.

FIG. 8 is a sectional view showing a bolt engagement portion, atelescopic insertion hole, and an EA insertion hole.

FIG. 9 is a sectional view taken along line IX-IX in FIG. 5, which showsa locked state.

FIG. 10 is an enlarged view of part X in FIG. 1.

FIG. 11 is a sectional view corresponding to FIG. 9, which shows a statewhere a stopper unit in an unlocked state is at a separating position.

FIG. 12 is a sectional view corresponding to FIG. 6, which shows theunlocked state.

FIG. 13 is a sectional view corresponding to FIG. 6, which shows theunlocked state.

FIG. 14 is a sectional view corresponding to FIG. 3, which shows a statein which a column unit is at an uppermost position.

FIG. 15 is a sectional view corresponding to FIG. 9, which shows a statewhere EA stoppers are at riding-over positions.

FIG. 16 is a sectional view corresponding to FIG. 9, which shows a statewhere the EA stoppers are at the riding-over positions.

FIG. 17 is an explanatory view showing a motion at the time of asecondary collision and is a sectional view corresponding to FIG. 6.

FIG. 18 is an explanatory view showing the motion at the time of thesecondary collision and is a bottom view corresponding to FIG. 4.

FIG. 19 is an explanatory view showing the motion at the time of thesecondary collision and is a sectional view corresponding to FIG. 6.

FIG. 20 is an explanatory view showing the motion at the time of thesecondary collision and is a sectional view corresponding to FIG. 6.

FIG. 21 is an explanatory view showing the motion at the time of thesecondary collision and is a sectional view corresponding to FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

Next, an embodiment of the present invention will be described on thebasis of drawings.

<Steering Device>

FIG. 1 is a perspective view of a steering device 1.

As shown in FIG. 1, the steering device 1 is installed in a vehicle. Thesteering device 1 adjusts the steering angle of vehicle wheels inaccordance with a rotation operation of a steering wheel 2.

The steering device 1 is provided with a column unit 11, a steeringshaft 12, a fixation bracket (front bracket 13 and rear bracket 14), anda switching unit 15. Each of the column unit 11 and the steering shaft12 is formed along an axis O1. Therefore, in the following description,a direction in which the axes O1 of the column unit 11 and the steeringshaft 12 extend will be simply referred to as an shaft axial direction,a direction orthogonal to the axes O1 will be referred to as a shaftradial direction, and a direction around the axes O1 will be referred toas a shaft circumferential direction in some cases.

The steering device 1 according to the present embodiment is installedin the vehicle in a state where the axis O1 intersects a front-reardirection. Specifically, the axis O1 of the steering device 1 extends tobecome closer to an upper side toward a rear side. However, in thefollowing description, a direction extending toward the steering wheel 2in the shaft axial direction of the steering device 1 will be simplyreferred to as a rearward direction and a direction extending to a sideopposite to the steering wheel 2 side will be simply referred to as afrontward direction (arrow FR), for the sake of convenience. A shaftradial direction that is parallel to a vertical direction in a statewhere the steering device 1 is attached to the vehicle will be simplyreferred to as a vertical direction (arrow UP represents upper side) anda shaft radial direction that is parallel to a lateral direction will besimply referred to as a lateral direction.

<Column Unit>

The column unit 11 is provided with an outer column 21 and an innercolumn 22.

The outer column 21 is attached to a vehicle body via the fixationbrackets 13 and 14.

The outer column 21 is mainly provided with a tubular holding portion 24and fastened portions 25.

FIG. 2 is a sectional view taken along line II-II in FIG. 1.

As shown in FIG. 2, the tubular holding portion 24 is formed into have atubular shape extending along the axis O1.

An outer ring of a front side bearing 27 is fitted into (press-fittedinto) an inner front end portion the tubular holding portion 24. Aportion of a rear part of the tubular holding portion 24 in the shaftcircumferential direction (in present embodiment, lower portion of outercolumn 21) is formed with a slit 28. The slit 28 penetrates the outercolumn 21 in the shaft radial direction and is open at a rear endsurface of the outer column 21.

FIG. 3 is a sectional view taken along line III-III in FIG. 1.

As shown in FIG. 3, the fastened portions 25 extend downward frompositions on the tubular holding portion 24, the positions facing eachother in the lateral direction with the slit 28 interposed therebetween.Each fastened portion 25 is formed with a through-hole 31 thatpenetrates the fastened portion 25 in the lateral direction.

As shown in FIG. 2, the inner column 22 is formed in a tubular shapeextending along the axis O1. The outer diameter of the inner column 22is smaller than the inner diameter of the tubular holding portion 24.The inner column 22 is inserted into the tubular holding portion 24. Theinner column 22 is configured to be able to move in the shaft axialdirection with respect to the tubular holding portion 24. An outer ringof a rear side bearing 32 is fitted into (press-fitted into) an innerrear end portion of the inner column 22. An outer ring of anintermediate bearing 34 is fitted into (press-fitted into) an innerfront end portion of the inner column 22.

FIG. 4 is a bottom view of the steering device 1.

As shown in FIG. 4, a portion of a rear part of the inner column 22 inthe shaft circumferential direction (in present embodiment, lowerportion) is formed with a pair of guide portions 33. The guide portions33 face each other in the lateral direction and each guide portion 33 isformed in a rail-like shape extending in the shaft axial direction(front-rear direction).

<Steering Shaft>

As shown in FIG. 2, the steering shaft 12 is provided with an innershaft 37 and an outer shaft 38.

The inner shaft 37 is formed in a hollow cylindrical shape extendingalong the axis O1. The inner shaft 37 is inserted into the tubularholding portion 24 with a gap provided therebetween. A front end portionof the inner shaft 37 is press-fitted into an inner ring of theabove-described front side bearing 27. Therefore, the inner shaft 37 issupported in the tubular holding portion 24 via the front side bearing27 such that the inner shaft 37 can rotate around the axis O1. The frontend portion of the inner shaft 37 (portion that protrudes up to positionahead of front side bearing 27) is connected to, for example, a lowershaft (not shown), a steering gear box (not shown), or the like via auniversal joint (not shown) or the like.

The outer shaft 38 extends in the shaft axial direction. The outer shaft38 is configured to be able to move in the shaft axial direction withrespect to the inner shaft 37 in accordance with movement of the innercolumn 22 in the shaft axial direction with respect to the outer column21. An inner circumferential surface of the outer shaft 38 is formedwith, for example, a female spline. A male spline formed on an outercircumferential surface of the inner shaft 37 is engaged with the femalespline. Accordingly, the outer shaft 38 moves in the shaft axialdirection with respect to the inner shaft 37 with the outer shaft 38restricted from rotating with respect to the inner shaft 37. Theexpansion and contraction structure of the steering shaft 12 can beappropriately changed.

A rear end portion of the outer shaft 38 is press-fitted into an innerring of the rear side bearing 32 in the inner column 22. A front endportion of the outer shaft 38 is press-fitted into an inner ring of theintermediate bearing 34 in the inner column 22. In this manner, theouter shaft 38 is configured to be able to rotate around the axis O1with respect to the inner column 22. A portion of the outer shaft 38that protrudes up to a position behind the inner column 22 is connectedwith the steering wheel 2. In the present embodiment, a configuration inwhich the outer shaft 38 is disposed behind the inner shaft 37 has beendescribed. However, the invention is not limited to the above-describedconfiguration and a configuration in which the outer shaft 38 isdisposed ahead of the inner shaft 37 may also be adopted.

<Hanger Bracket>

As shown in FIGS. 2 and 3, a hanger bracket 51 is fixed to a lowerportion of the inner column 22 such that the hanger bracket 51 faces alower side. The hanger bracket 51 is formed through press working of ametal plate, for example. The hanger bracket 51 is exposed to theoutside of the tubular holding portion 24 through the slit 28 of thetubular holding portion 24. The hanger bracket 51 is formed in a U-shapethat is open to the lower side in a front view as seen in the shaftaxial direction.

FIG. 5 is an enlarged perspective view of the hanger bracket 51 and alock mechanism 53.

As shown in FIG. 5, the hanger bracket 51 is provided with a top plateportion 61 and a pair of side plate portions 62, the side plate portions62 extending downward from opposite end portions of the top plateportion 61 in the lateral direction.

The top plate portion 61 is provided with a thick portion 61 a that ispositioned on a rear end portion side and a thin portion 61 b that isaligned with the thick portion 61 a while being positioned ahead of thethick portion 61 a. The thick portion 61 a and the thin portion 61 b maybe aligned with each other via a level difference or may be smoothlyaligned with each other via an inclined surface or the like. A centralportion of the top plate portion 61 in the lateral direction is formedwith an EA elongated hole (guide hole) 64 that penetrates the top plateportion 61 in the vertical direction. The EA elongated hole 64 linearlyextends over the thick portion 61 a and the thin portion 61 b in theshaft axial direction.

The hanger bracket 51 is fixed to the inner column 22 by means of afixation member (telescopic restricting portion) 71.

Specifically, a bolt 72 of the fixation member 71 is inserted into arear end portion of the EA elongated hole 64 from below. The fixationmember 71 has a function as a telescopic restricting portion. Thefixation member 71 restricts the inner column 22 from moving forwardwith respect to the outer column 21 at the time of a telescopic motion.An axial portion 72 a of the bolt 72 penetrates an insertion hole 22 a(refer to FIG. 6) formed in the lower portion of the inner column 22 inthe vertical direction. In the present embodiment, the inner diameter ofthe insertion hole 22 a is larger than the outer diameter of the axialportion 72 a. Specifically, a gap is provided between an outercircumferential surface of the axial portion 72 a and an innercircumferential surface of the insertion hole 22 a. In an example shownin the drawing, a head portion 72 b of the bolt 72 is provided with atapered portion of which the diameter gradually decreases toward a baseend portion (lower end portion) of the bolt 72.

A tip end portion (upper end portion) of the axial portion 72 a isscrewed into a nut 73 of the fixation member 71 in the inner column 22.That is, the hanger bracket 51 is fixed to the inner column 22 with thetop plate portion 61 (thick portion 61 a) and the inner column 22interposed between the head portion 72 b of the bolt 72 and the nut 73in the vertical direction. Note that, a method of fixing the hangerbracket 51 can be appropriately changed. For example, the hanger bracket51 may be fixed to the inner column 22 with a rivet or the like.

The hanger bracket 51 is fixed to the inner column 22 in a state where arear end portion of the top plate portion 61 is disposed inward of theguide portions 33. It is sufficient that at least a portion of thehanger bracket 51 is disposed inward of the guide portions 33.

FIG. 6 is a sectional view taken along line VI-VI in FIG. 5.

As shown in FIG. 6, each side plate portion 62 is formed over the entirelength of the top plate portion 61. A portion of the side plate portion62 other than a front end portion is formed with telescopic lock teeth(telescopic engagement portion) 75 that protrude downward. Each of thetelescopic lock teeth 75 is formed in a trapezoidal shape in a side viewas seen in the lateral direction. Specifically, a rear surface of thetelescopic lock tooth 75 is an inclined surface that extends to becomecloser to the lower side toward a front side from the rear side. A lowersurface of the telescopic lock tooth 75 is a flat surface that linearlyextends in the shaft axial direction. A front surface of the telescopiclock tooth 75 is a flat surface that linearly extends in the verticaldirection. The shape of each surface of the telescopic lock tooth 75 canbe appropriately changed.

A plurality of the telescopic lock teeth 75 are formed at intervals inthe shaft axial direction. In the present embodiment, the telescopiclock teeth 75 formed on the respective side plate portions 62, whichcorrespond to each other, are formed at the same positions (at samepitches) in the shaft axial direction. The number of telescopic lockteeth 75 or the pitches at which the telescopic lock teeth 75 are formedcan be appropriately changed. The pitches at which the telescopic lockteeth 75 are formed may be different between the right side plateportion 62 and the left side plate portion 62.

A front end portion of each side plate portion 62 is formed with a frontside telescopic restricting portion (telescopic restricting portion) 77.The front side telescopic restricting portion 77 restricts the innercolumn 22 from moving rearward with respect to the outer column 21 atthe time of the telescopic motion. The front side telescopic restrictingportion 77 is formed in a trapezoidal shape of which the width in theshaft axial direction gradually decreases toward the lower side. Theheight of the front side telescopic restricting portion 77 in thevertical direction is greater than that of the telescopic lock tooth 75.A rear surface of the front side telescopic restricting portion 77 isformed into a flat surface that linearly extends in the verticaldirection. A front surface of the front side telescopic restrictingportion 77 is an inclined surface that extends to become closer to therear side toward the lower side.

<EA Wire>

As shown in FIGS. 4 and 5, an energy absorbing (EA) wire 52 isinterposed between the hanger bracket 51 and the fixation member 71. TheEA wire 52 is formed in an M-shape in a plan view as seen in thevertical direction. Specifically, the EA wire 52 is provided with a pairof leg portions 81 and a connection portion 82 that connects the pair ofleg portions 81 to each other.

The leg portion 81 extends in the shaft axial direction. In the presentembodiment, the leg portion 81 is inclined to become closer to an innerside in the lateral direction toward the front side. The leg portion 81is disposed between the guide portion 33 and the top plate portion 61 ateach of opposite end portions of the top plate portion 61 in the lateraldirection.

The connection portion 82 is routed around a front side of the headportion 72 b of the bolt 72 and then is connected to a rear end portionof each leg portion 81 at a rear side of the hanger bracket 51. Notethat, the wire diameter of the EA wire 52 can be appropriately changedaccording to a necessary bending load or the like.

Here, as shown in FIG. 1, the front bracket 13 described above connectsthe outer column 21 and the vehicle body to each other via a pivot shaft86. The front bracket 13 is formed in a U-shape that is open to thelower side in a front view as seen in the shaft axial direction. Thefront bracket 13 surrounds a front end portion of the outer column 21from above and opposite sides in the lateral direction. Front side walls13 a of the front bracket 13 that are positioned on opposite sides inthe lateral direction are connected to the outer column 21 via the pivotshaft 86. Accordingly, the outer column 21 is supported by the frontbracket 13 such that the outer column 21 can rotate around an axis O2 ofthe pivot shaft 86 that extends in the lateral direction.

As shown in FIG. 3, the rear bracket 14 connects the outer column 21,the hanger bracket 51, and the vehicle body to each other via a lockbolt 100 of the lock mechanism 53, which will be described later. Therear bracket 14 is formed in a U-shape that is open to the lower side ina front view as seen in the shaft axial direction. The rear bracket 14surrounds an upper side of the outer column 21 and opposite sides of theouter column 21 in the lateral direction.

Specifically, the rear bracket 14 is provided with side plate portions90 disposed on right and left sides of the column unit 11 and a bridgeportion 91 that connects the side plate portions 90 to each other.

The side plate portion 90 is formed in an L-shape in a front view asseen in the shaft axial direction. The side plate portion 90 is providedwith a rear side wall 92 that extends in the vertical direction and aprojecting portion 93 that projects outward in the lateral directionfrom an upper end portion of the rear side wall 92.

Each rear side wall 92 is formed with a tilting guide hole 96 thatpenetrates the rear side wall 92 in the lateral direction. The tiltingguide hole 96 is an elongated hole that extends to become closer to therear side toward the upper side. Specifically, the tilting guide hole 96is formed in an arc shape that protrudes rearward.

The projecting portions 93 are connected to the vehicle body.

The bridge portion 91 is connected to the upper end portion of each rearside wall 92. The bridge portion 91 is formed in an arch shape thatprotrudes upward. The bridge portion 91 restricts the column unit 11from rising when the column unit 11 performs a tilting motion (angleadjustment of column unit 11 around axis O2).

<Switching Unit>

As shown in FIG. 4, the switching unit 15 is mainly provided with thelock mechanism 53, an operation lever 54, and a fastening cam 55.

<Lock Mechanism>

FIG. 7 is an exploded perspective view of the lock mechanism 53.

As shown in FIG. 7, the lock mechanism 53 is mainly provided with thelock bolt 100 and a stopper unit 101 that is attached to the lock bolt100.

As shown in FIG. 3, the lock bolt 100 is formed to have a diametersmaller than that of the through-hole 31 formed in each fastened portion25. The lock bolt 100 penetrates the fastened portions 25 and the rearbracket 14 in the lateral direction through the through-hole 31 of eachfastened portion 25 and the tilting guide holes 96 of the rear bracket14. In the following description, a direction in which an axis O3 of thelock bolt 100 extends will be simply referred to as a bolt axialdirection (lateral direction), a direction orthogonal to the axis O3will be referred to as a bolt radial direction, and a direction aroundthe axis O3 will be referred to as a bolt circumferential direction, insome cases.

As shown in FIG. 7, an intermediate portion of the lock bolt 100 in thelateral direction is formed with a bolt engagement portion 103. The boltengagement portion 103 is configured with bolt recess portions 103 a andbolt protruding portions 103 b alternately disposed.

The bolt recess portion 103 a is recessed inward in the bolt radialdirection with respect to an outer circumferential surface of the lockbolt 100 and extends in the bolt axial direction. A plurality of thebolt recess portions 103 a are formed at intervals in the boltcircumferential direction over the entire circumference of the lock bolt100. That is, regarding the lock bolt 100, the bolt protruding portion103 b that projects outward in the bolt radial direction with respect tothe bolt recess portions 103 a is formed between the bolt recessportions 103 a that are adjacent to each other in the boltcircumferential direction. It is sufficient that the bolt engagementportion 103 is provided with at least one bolt recess portion 103 a(bolt protruding portion 103 b). The bolt protruding portion 103 b maybe formed to protrude outward in the bolt radial direction with respectto the outer circumferential surface of the lock bolt 100.

The stopper unit 101 is mainly provided with a holder 110, a telescopicstopper 111, EA stoppers 112, and a first urging member 113.

The holder 110 is formed through press working of a metal plate, forexample. The holder 110 is formed in a U-shape that is open to the upperside in a front view. Specifically, the holder 110 is provided with apair of holder side walls 115 facing each other in the lateral directionand a bottom wall 116 that connects lower ends of the holder side walls115 to each other.

Each holder side wall 115 is formed with a holder insertion hole 120that penetrates the holder side wall 115 in the lateral direction. Thebolt engagement portion 103 of the lock bolt 100 is inserted into theholder insertion holes 120. The shape of each holder insertion hole 120is the same as that of the bolt engagement portion 103 in a side view asseen in the lateral direction. That is, an inner circumferential surfaceof each holder insertion hole 120 is formed with holder protrudingportions 120 a that project radially inward. Each holder protrudingportion 120 a is fitted into each bolt recess portion 103 a in a statewhere the lock bolt 100 is inserted into the holder insertion hole 120.Meanwhile, a portion that is positioned between the holder protrudingportions 120 a that are adjacent to each other in the boltcircumferential direction constitutes a holder recess portion 120 b thatis recessed outward in the bolt radial direction with respect to theholder protruding portions 120 a. Each bolt protruding portion 103 b isfitted into each holder recess portion 120 b in a state where the lockbolt 100 is inserted into the holder insertion hole 120.

The width of the holder recess portion 120 b (with in boltcircumferential direction) is set to be the same as that of the boltprotruding portion 103 b. The width of the holder protruding portion 120a is set to be the same as that of the bolt recess portion 103 a.Therefore, the holder 110 is engaged with the lock bolt 100 in the boltcircumferential direction. In the present embodiment, the holder 110integrally rotates with the lock bolt 100. It is at least one pair of apair of sufficient that the widths of the holder recess portion 120 band the bolt protruding portion 103 b and a pair of the widths of theholder protruding portion 120 a and the bolt recess portion 103 a arethe same as each other. The number of holder protruding portions 120 a(holder recess portions 120 b) and the number of bolt recess portions103 a (bolt protruding portions 103 b) may not be the same as eachother.

An intermediate portion of each holder side wall 115 in the verticaldirection is formed with a curved claw 123. The curved claw 123 extendsforward from each holder side wall 115 and then is curved inward in thelateral direction.

An intermediate portion in the lateral direction of a front edge of thebottom wall 116 is formed with a deformation portion 124. Thedeformation portion 124 is formed in an L-shape in a side view as seenin the lateral direction. Specifically, the deformation portion 124 isprovided with a tongue piece portion 125 and a holding portion 126 thatis aligned with a tip end of the tongue piece portion 125.

The tongue piece portion 125 is formed in a thin plate-like shape ofwhich the width is smaller than the width (width in lateral direction)of the bottom wall 116. The tongue piece portion 125 extends forwardfrom the front edge of the bottom wall 116 and then is curved upward.

As shown in FIGS. 6 and 7, the holding portion 126 is formed to have awidth larger than that of the tongue piece portion 125 in a front viewas seen in the shaft axial direction. The holding portion 126 has acurved shape that protrudes rearward in a side view as seen in thelateral direction.

The telescopic stopper 111 is rotatably supported by the lock bolt 100while being disposed inward of the holder 110. As shown in FIG. 6, thetelescopic stopper 111 is provided with a telescopic ring 131 that isformed with a telescopic insertion hole 130. The telescopic insertionhole 130 is a circular hole of which the diameter is larger than that ofa maximum outer diameter portion (outer circumferential surface of boltprotruding portion 103 b) of the bolt engagement portion 103 of the lockbolt 100. The bolt engagement portion 103 of the lock bolt 100 isinserted into the telescopic insertion hole 130.

A portion of the telescopic ring 131 in the bolt circumferentialdirection is formed with a front side stopper 132. The front sidestopper 132 protrudes outward in the bolt radial direction from thetelescopic ring 131 and has a plate-like shape of which the width in thelateral direction is larger than that of the telescopic ring 131. At thetime of the telescopic motion, the above-described front side telescopicrestricting portions 77 abut onto of the front side stopper 132 from thefront side at a maximum expansion position of the inner column 22.Therefore, the inner column 22 is restricted from moving rearward withrespect to the outer column 21. As shown in FIG. 6, the front sidestopper 132 is engaged with the above-described holding portion 126 froma first side (lower side in example shown in drawing) in the boltcircumferential direction.

A portion of the telescopic ring 131 that is positioned closer to asecond side (upper side in example shown in drawing) in the boltcircumferential direction than the front side stopper 132 is formed withan engagement claw 133 that protrudes outward in the bolt radialdirection. The engagement claw 133 is engaged with the above-describedholding portion 126 from the second side in the bolt circumferentialdirection. In this manner, the front side stopper 132 and the engagementclaw 133 are engaged with the holding portion 126 from opposite sides inthe bolt circumferential direction and thus the telescopic stopper 111is restricted from rotating with respect to the lock bolt 100.

A portion of the telescopic ring 131 that is positioned closer to thesecond side in the bolt circumferential direction than the engagementclaw 133 is formed with a rear side stopper 135. The rear side stopper135 protrudes outward in the bolt radial direction from the telescopicring 131. The rear side stopper 135 is formed to have a width largerthan that of the telescopic ring 131 and is formed to have a widthsmaller than that of the front side stopper 132. The front side stopper132 is disposed between the above-described holder side walls 115. Therear side stopper 135 faces the head portion 72 b of the bolt 72 in theshaft axial direction. That is, at the time of the telescopic motion,the rear side stopper 135 abuts onto of the head portion 72 b of thebolt 72 at a maximum contraction position of the inner column 22.Therefore, the inner column 22 is restricted from moving forward withrespect to the outer column 21. In this manner, a stroke (telescopicstroke) at the time of the telescopic motion is set to be a lengthbetween the fixation member 71 and the front side telescopic restrictingportions 77 in the front-rear direction. The rear side stopper 135 isformed with a bolt receiving portion 136 that is recessed downward. Thebolt receiving portion 136 is a portion that abuts onto the head portion72 b (tapered portion) of the bolt 72 at the maximum contractionposition of the inner column 22 at the time of the telescopic motion.

As shown in FIG. 7, a pair of the EA stoppers 112 is provided on rightand left sides of the telescopic stopper 111 while being positionedinward of the holder 110. The configurations of the EA stoppers 112 arethe same as each other. Therefore, the following description will bemade by using one EA stopper 112 as an example.

The EA stopper 112 is provided with an EA ring 141 that is formed withan EA insertion hole 140. The bolt engagement portion 103 of the lockbolt 100 is inserted into the EA insertion hole 140 such that the boltengagement portion 103 can rotate with respect to the EA stopper 112.

FIG. 8 is a sectional view showing the bolt engagement portion 103, thetelescopic insertion hole 130, and the EA insertion hole 140.

As shown in FIG. 8, an inner circumferential surface of the EA insertionhole 140 is formed with EA protruding portions 140 a that project inwardin the bolt radial direction. The width of the EA protruding portions140 a in the bolt circumferential direction is smaller than that of thebolt recess portions 103 a. The EA protruding portions 140 a areaccommodated in the bolt recess portions 103 a in a state where the lockbolt 100 is inserted into the EA insertion hole 140.

Meanwhile, a portion that is positioned between the EA protrudingportions 140 a that are adjacent to each other in the boltcircumferential direction constitutes a EA recess portion 140 b that isrecessed outward in the bolt radial direction with respect to the EAprotruding portions 140 a. The width of the EA recess portions 140 b inthe bolt circumferential direction is larger than that of the boltprotruding portions 103 b. The bolt protruding portions 103 b areaccommodated in the EA recess portions 140 b in a state where the lockbolt 100 is inserted into the EA insertion hole 140.

In this manner, the EA protruding portion 140 a is accommodated in thebolt recess portion 103 a in a state where a gap S in the boltcircumferential direction is provided between the EA protruding portion140 a and the bolt protruding portion 103 b that is adjacent to the EAprotruding portion 140 a in the bolt circumferential direction. That is,the gap S functions as a play when the lock bolt 100 rotates withrespect to the EA stoppers 112. Therefore, the lock bolt 100 isconfigured to be able to rotate with respect to the EA stoppers 112until the EA protruding portions 140 a and the bolt protruding portion103 b abut onto each other in the bolt circumferential direction.

FIG. 9 is a sectional view taken along line IX-IX in FIG. 5.

As shown in FIGS. 5 and 9, a portion of the EA ring 141 in the boltcircumferential direction is formed with an abutting portion 144. Theabutting portion 144 protrudes outward in the bolt radial direction fromthe EA ring 141. The abutting portion 144 is configured to be able to beengaged with the telescopic lock tooth 75 with the EA ring 141 rotatingin accordance with rotation of the lock bolt 100. Specifically, the lockmechanism 53 rotates between an abutting position (locked state) and aseparating position (unlocked state (refer to FIG. 11)). At the abuttingposition, the abutting portion 144 abuts onto, for example, a lowersurface of the telescopic lock tooth 75 from the lower side. At theseparating position, the abutting portion 144 is moved downward to beseparated from the lower surface of the telescopic lock tooth 75.

A base end portion of the abutting portion 144 is formed with an EA clawportion 145. The EA claw portion 145 protrudes in a direction thatintersects a direction in which the abutting portion 144 extends. At theabutting position, the EA claw portion 145 enters a space between thetelescopic lock teeth 75 that are adjacent to each other in the shaftaxial direction. The EA claw portion 145 is configured such that thetelescopic lock tooth 75 can be engaged with the EA claw portion 145from the rear side at the abutting position.

The EA claw portion 145 in the present embodiment is formed in atriangular shape in a side view as seen in the lateral direction.

A rear surface of the EA claw portion 145 is formed into a flat surfaceextending in the vertical direction. A front surface of the EA clawportion 145 is formed into an inclined surface that is inclined tobecome closer to the front side toward the lower side.

The first urging member 113 is, for example, a double torsion spring.The first urging member 113 is interposed between the bottom wall 116 ofthe holder 110 and the EA stoppers 112. The first urging member 113urges the EA stoppers 112 toward the abutting position (in direction inwhich abutting portion 144 is pressed against telescopic lock tooth 75).Therefore, the above-described EA protruding portions 140 a are engagedwith the bolt protruding portions 103 b in a direction toward theabutting position (direction A2) in the bolt circumferential direction.Therefore, the EA stoppers 112 integrally rotate with the lock bolt 100.The first urging member 113 is not limited to a double torsion spring.

As shown in FIG. 1, the operation lever 54 is connected to a first endportion (in example shown in drawing, left end portion) of the lock bolt100 in the lateral direction. The operation lever 54 is configured to beable to rotate around the axis O3 along with the lock mechanism 53.

As shown in FIG. 3, the fastening cam 55 is interposed between theoperation lever 54 and the rear side wall 92 of the rear bracket 14. Thefastening cam 55 is configured such that the thickness thereof in thelateral direction changes as the operation lever 54 rotates. Thesteering device 1 is configured such that the fastened portions 25approach each other or the fastened portions 25 are separated from eachother in the lateral direction via the rear side walls 92 (width(interval) of slit 28 in lateral direction increases or decreases) whenthe thickness of the fastening cam 55 changes. Specifically, when theoperation lever 54 is rotated such that the thickness of the fasteningcam 55 increases, the fastened portions 25 approach each other alongwith the rear side walls 92 and the diameter of the tubular holdingportion 24 decreases. Accordingly, the inner column 22 is clamped by thetubular holding portion 24 and the inner column 22 is restricted frommoving in the shaft axial direction with respect to the outer column 21(locked state). Meanwhile, when the operation lever 54 is rotated suchthat the thickness of the fastening cam 55 decreases, the fastenedportions 25 are separated from each other along with the rear side walls92 and the diameter of the tubular holding portion 24 increases.Accordingly, the inner column 22 clamped by the tubular holding portion24 is released. As a result, the inner column 22 is allowed to move inthe shaft axial direction with respect to the outer column 21 (unlockedstate).

Second urging members 150 are interposed between opposite end portionsof the above-described lock bolt 100 in the lateral direction and theabove-described projecting portions 93 of the rear bracket 14. Thesecond urging members 150 are for achieving a tilt balance. The secondurging members 150 are, for example, coil springs. Upper end portions ofthe second urging members 150 are connected to the projecting portions93. Lower end portions of the second urging members 150 are connected tothe lock bolt 100. The second urging members 150 urge the column unit11, the steering shaft 12, or the like upward via the lock bolt 100.Therefore, the column unit 11 is prevented from being lowered due to theown weight of the column unit 11 at the time of an unlocking operation.

FIG. 10 is an enlarged view of part X in FIG. 1.

As shown in FIG. 10, an upper portion of the tubular holding portion 24of the above-described outer column 21 is formed with a bumping portion152. The bumping portion 152 projects upward from the tubular holdingportion 24. The bumping portion 152 bumps against the bridge portion 91of the rear bracket 14 from the lower side at an uppermost position ofthe tilting motion. That is, the dimensions of the bumping portion 152are set such that the bumping portion 152 bumps against the bridgeportion 91 before the lock bolt 100 comes into contact with an upper endinner circumferential edge of the tilting guide hole 96 at the time ofthe tilting motion.

<Effect>

Next, the effect of the above-described steering device 1 will bedescribed. The following description will be made focusing on thetilting motion, the telescopic motion, and a motion at the time ofsecondary collision. The following description will be made on anassumption that a state in which the EA stopper 112 is at the abuttingposition as shown in FIG. 9 is an initial state.

<Tilting Motion and Telescopic Motion>

As shown in FIG. 1, in a case where the position of the steering wheel 2in the front-rear direction or the angle of the steering wheel 2 isadjusted, the operation lever 54 is rotated first such that the steeringdevice 1 enters the unlocked state. Specifically, the operation lever 54is rotated in a direction (for example, downward direction) in which thethickness of the fastening cam 55 decreases. Then, the fastened portions25 are separated from each other along with the rear side walls 92 andthe diameter of the tubular holding portion 24 (slit 28) increases.Accordingly, the inner column 22 clamped by the tubular holding portion24 is released and the outer column 21 clamped by the rear side walls 92is released. As a result, it becomes possible to perform the telescopicmotion and the tilting motion.

FIG. 11 is a sectional view corresponding to FIG. 9, which shows a statewhere the stopper unit 101 is at the separating position.

Here, as described above, the bolt engagement portion 103 of the lockbolt 100 and the holder protruding portions 120 a (holder recessportions 120 b) of the holder 110 are engaged with each other in thebolt circumferential direction. Therefore, as shown in FIG. 11, in aprocess in which the operation lever 54 is rotated such that theunlocked state is entered, the holder 110 rotates in a direction A1around the axis O3 (counter-clockwise direction in FIG. 11) along withthe lock bolt 100.

Furthermore, the telescopic stopper 111 is restricted from rotating withrespect to the lock bolt 100 since the front side stopper 132 and theengagement claw 133 are engaged with the holding portion 126 of theholder 110 from opposite sides in the bolt circumferential direction.Therefore, the telescopic stopper 111 held by the holder 110 rotates inthe direction A1 around the axis O3 along with the lock bolt 100.

Meanwhile, as shown in FIG. 9, the EA stoppers 112 are urged toward theabutting position by the first urging member 113. Therefore, the EAprotruding portions 140 a of the EA stoppers 112 are engaged with thebolt protruding portions 103 b in the direction A2 around the axis O3(clockwise direction in FIG. 9). Therefore, as shown in FIG. 11, the EAstoppers 112 also rotate in the direction A1 around the axis O3 alongwith the lock bolt 100 when the operation lever 54 is rotated such thatthe unlocked state is entered.

As a result, the EA stoppers 112 move to the separating position as theoperation lever 54 moves such that the unlocked state is entered.

The steering wheel 2 is pressed forward in the unlocked state. Then, thesteering wheel 2 moves forward with respect to the outer column 21 alongwith the inner column 22 and the steering shaft 12. When the steeringwheel 2 is pulled rearward in the unlocked state, the steering wheel 2moves rearward with respect to the outer column 21 along with the innercolumn 22 and the steering shaft 12. In this manner, it is possible toadjust the position of the steering wheel 2 in the front-rear directionto a certain position.

In the unlocked state, the front side stopper 132 of the telescopicstopper 111 overlaps the front side telescopic restricting portions 77in a front view. Therefore, the front side stopper 132 abuts onto thefront side telescopic restricting portions 77 at the maximum expansionposition of the inner column 22. Accordingly, the inner column 22 isrestricted from moving rearward with respect to the outer column 21.

FIG. 12 is a sectional view corresponding to FIG. 6, which shows theunlocked state.

As shown in FIG. 12, when the telescopic stopper 111 rotates inaccordance with rotation of the lock bolt 100 at the time of theunlocking operation, the front side stopper 132 and the front sidetelescopic restricting portions 77 face each other in the front-reardirection. At this time, a surface of the front side stopper 132 thatfaces the front side and surfaces of the front side telescopicrestricting portions 77 that face the rear side (facing surfaces offront side stopper 132 and front side telescopic restricting portions77) are disposed to be substantially parallel to each other. Therefore,the front side stopper 132 and the front side telescopic restrictingportions 77 come into surface-contact with each other when the frontside stopper 132 and the front side telescopic restricting portions 77abut onto each other. As a result, the inner column 22 can be reliablyrestricted from moving rearward with respect to the outer column 21. Adamage to the telescopic stopper 111 that is caused by a load generatedat the time of abutting.

Meanwhile, in the unlocked state, the rear side stopper 135 of thetelescopic stopper 111 overlaps the head portion 72 b of the bolt 72 ina front view. Therefore, the bolt receiving portion 136 of the rear sidestopper 135 and the head portion 72 b (tapered portion) of the bolt 72abut onto each other at the maximum contraction position of the innercolumn 22. Accordingly, the inner column 22 is restricted from movingforward with respect to the outer column 21.

FIG. 13 is a sectional view corresponding to FIG. 6, which shows theunlocked state.

As shown in FIG. 13, when the telescopic stopper 111 rotates inaccordance with rotation of the lock bolt 100 at the time of theunlocking operation, the bolt receiving portion 136 is inclined tobecome closer to the lower side toward the rear side (for example, anglewith respect to front-rear direction is approximately 45°). When theinner column 22 is moved forward in this state, the head portion 72 b(tapered portion) of the bolt 72 abuts onto the bolt receiving portion136 of the rear side stopper 135 from a diagonally upper side.Specifically, the bolt receiving portion 136 and the tapered portion ofthe head portion 72 b come into contact (surface-contact) with eachother in a state of being inclined with respect to the front-reardirection. Accordingly, it is possible to suppress the telescopicstopper 111 rotating such that the locked state is entered. At thistime, a load that acts in a normal direction of the bolt receivingportion 136 between the bolt receiving portion 136 and the head portion72 b is decomposed into a load in a forward direction (locked state) anda load in a downward direction (unlocked state). That is, a component ofthe load that acts between the bolt receiving portion 136 and the headportion 72 b at the time of the telescopic motion can be caused to actin a direction in which the telescopic stopper 111 is rotated such thatthe unlocked state is entered (direction different from direction forlocked state). Therefore, it is possible to reliably restrict the innercolumn 22 from moving forward with respect to the outer column 21 whilesuppressing unexpected rotation of the telescopic stopper 111.

When adjusting the angle of the steering wheel 2 in the unlocked statesuch that the steering wheel 2 faces the upper side, the steering wheel2 is pressed upward. Then, the steering wheel 2 swings upward around theaxis O2 along the tilting guide holes 96, along with the column unit 11and the steering shaft 12.

Meanwhile, when adjusting the angle of the steering wheel 2 in theunlocked state such that the steering wheel 2 faces the lower side, thesteering wheel 2 is pulled down. Then, the steering wheel 2 swingsdownward around the axis O2 along the tilting guide holes 96, along withthe column unit 11 and the steering shaft 12. In this manner, it ispossible to adjust the angle of the steering wheel 2 to a certainposition.

FIG. 14 is a sectional view corresponding to FIG. 3, which shows a statein which the column unit 11 is at the uppermost position.

As shown in FIG. 14, in a process in which the column unit 11 swingsupward, the lock bolt 100 moves upward inside the tilting guide holes96. At this time, the bumping portion 152 of the outer column 21 abutsonto the bridge portion 91 from the lower side before the lock bolt 100bumps against the upper end inner circumferential edges of the tiltingguide holes 96. Accordingly, the column unit 11 is restricted fromswinging upward.

Next, as shown in FIG. 3, after the position of the steering wheel 2 isadjusted to a desired position, the operation lever 54 is rotated suchthat the steering device 1 enters the locked state. Specifically, theoperation lever 54 is rotated in a direction (for example, upwarddirection) in which the thickness of the fastening cam 55 increases.Then, the fastened portions 25 are approach each other along with therear side walls 92 and the diameter of the tubular holding portion 24(slit 28) decreases. Accordingly, the inner column 22 is clamped by thetubular holding portion 24 and the outer column 21 is clamped by therear side walls 92. As a result, the telescopic motion and the tiltingmotion are restricted.

As shown in FIGS. 9 and 11, when the operation lever 54 is rotated suchthat the unlocked state is entered, the holder 110 and the telescopicstopper 111 rotate in the direction A1 around the axis O3 along with thelock bolt 100.

Meanwhile, when the lock bolt 100 is rotated in the direction A2 suchthat the locked state is entered, the bolt protruding portions 103 bmove to be separated from the EA protruding portions 140 a in thedirection A2. However, since the EA stoppers 112 are urged toward theabutting position by the first urging member 113, the EA stoppers 112are rotated in the direction A2 in accordance with rotation of the lockbolt 100 in the direction A2. Regarding the EA stopper 112, the EA clawportion 145 enters a space between the adjacent telescopic lock teeth 75and the abutting portion 144 abuts onto a lower surface of thetelescopic lock tooth 75 from the lower side. That is, when theoperation lever 54 is moved such that the locked state is entered, theEA stoppers 112 move to the abutting position.

FIGS. 15 and 16 are sectional view corresponding to FIG. 9, which show astate where the EA stoppers 112 are at riding-over positions.

Here, as shown in FIG. 15, there is a case where the EA claw portions145 interfere with the telescopic lock teeth 75 during a process inwhich the EA stoppers 112 are rotated in the direction A2 such that thelocked state is entered (riding-over position).

With regard to this, in the present embodiment, the EA stoppers 112 areurged in the direction A2 by the first urging member 113. The EAprotruding portion 140 a is accommodated in the bolt recess portion 103a in a state where the gap S is provided between the EA protrudingportion 140 a and the bolt protruding portion 103 b that is adjacent tothe EA protruding portion 140 a in the bolt circumferential direction.

Therefore, as shown in FIG. 16, even in a case where the EA stoppers 112are at the riding-over positions, when the lock bolt 100 (operationlever 54) is rotated in the direction A2, the lock bolt 100 or the likerotate in the direction A2 with respect to the EA stoppers 112. That is,the lock bolt 100 rotates (idles) with respect to the EA stoppers 112such that the gap S is filled. Accordingly, it is possible to move theoperation lever 54 such that the locked state is entered even when theEA stoppers 112 are at the riding-over positions.

<At Time of Secondary Collision>

Next, a motion at the time of the secondary collision will be described.

At the time of the secondary collision, a collision load toward thefront side acts on the steering wheel 2 from a driver. In a case wherethe magnitude of the collision load is equal to or greater than apredetermined level, the steering wheel 2 moves forward with respect tothe outer column 21 along with the inner column 22 and the steeringshaft 12. Specifically, in the steering device 1, the inner column 22 orthe like moves forward with respect to the outer column 21 with an outercircumferential surface of the inner column 22 sliding on an innercircumferential surface of the outer column 21.

Due to a sliding friction between the outer column 21 and the innercolumn 22, an impact load that is applied to the driver at the time ofthe secondary collision is alleviated.

FIG. 17 is an explanatory view showing a motion at the time of thesecondary collision and is a sectional view corresponding to FIG. 6.

Here, as shown in FIG. 17, when the hanger bracket 51 is moved forwardalong with the inner column 22 in a state where the EA stoppers 112 areat the abutting positions, the telescopic lock teeth 75 and the EA clawportions 145 are engaged with each other in the shaft axial direction.Accordingly, the hanger bracket 51 is restricted from moving forwardwith respect to the outer column 21. As a result, the inner column 22moves forward with respect to the hanger bracket 51, the outer column21, and the lock mechanism 53 (hereinafter, referred to as “hangerbracket 51 and like”) along with the fixation member 71 (collapsestroke).

Meanwhile, as shown in FIG. 16, when the hanger bracket 51 is movedforward along with the inner column 22 in a state where the EA stoppers112 are at the riding-over positions, the EA claw portions 145 ride overthe telescopic lock teeth 75. Then, as shown in FIG. 9, the EA stoppers112 are moved to the abutting position due to an urging force of thefirst urging member 113 and each EA claw portion 145 enters a spacebetween the adjacent telescopic lock teeth 75. Thereafter, as shown inFIG. 17, the telescopic lock teeth 75 are engaged with the EA clawportions 145 and the hanger bracket 51 and the like are restricted frommoving forward with respect to the outer column 21.

As described above, in the present embodiment, the hanger bracket 51 andthe EA stoppers 112 are engaged with each other regardless of thepositions (abutting positions or riding-over positions) of the EAstoppers 112 in the locked state. Therefore, at the time of thesecondary collision, the inner column 22 moves forward with respect tothe hanger bracket 51 and the like.

FIG. 18 is an explanatory view showing the motion at the time of thesecondary collision and is a bottom view corresponding to FIG. 4.

As shown in FIG. 18, at the time of the collapse stroke, the bolt 72 ofthe fixation member 71 moves forward with respect to the hanger bracket51 and the like along the EA elongated hole 64, in accordance withforward movement of the inner column 22. When the bolt 72 moves forward,the connection portion 82 of the EA wire 52 is pulled forward. Then, theleg portions 81 are drawn forward (crumpled) through a rear side of thehanger bracket 51 and the leg portions 81 are plastically deformed. Atthis time, the leg portions 81 are plastically deformed while beingguided by the guide portions 33 provided for the inner column 22. Inaddition, an impact load that is applied to the driver at the time ofthe secondary collision is alleviated due to a bending load generatedwhen the EA wire 52 (leg portions 81) is plastically deformed, a slidingfriction generated when the EA wire 52 slides on the inner column 22,the hanger bracket 51, or the guide portions 33, a sliding frictionbetween the hanger bracket 51 and the inner column 22, or the like. Inaddition, since the guide portions 33 are provided, the leg portions 81can move along the rear side of the hanger bracket 51 without beingspread and an appropriate impact absorption load can be achieved.

FIG. 19 is an explanatory view showing the motion at the time of thesecondary collision and is a sectional view corresponding to FIG. 6.

As shown in FIG. 19, in a process in which the fixation member 71 movesforward, the fixation member 71 enters the thin portion 61 b afterpassing through the thick portion 61 a. At the thin portion 61 b, thebolt 72 is inclined with, for example, a contact point between the bolt72 and the inner column 22 as a fulcrum due to a pulling force of the EAwire 52. Therefore, the head portion 72 b of the bolt 72 slides on thethin portion 61 b in a state of being in local contact with the thinportion 61 b. In addition, an impact load that is applied to the driverat the time of the secondary collision is alleviated due to a slidingfriction between the bolt 72 and the thin portion 61 b.

FIGS. 20 and 21 are explanatory views showing the motion at the time ofthe secondary collision and are sectional views corresponding to FIG. 6.

As shown in FIG. 20, at the time of the collapse stroke, the fixationmember 71 moves forward with respect to the lock mechanism 53 and thusthe head portion 72 b of the bolt 72 comes into contact with the rearside stopper 135 of the telescopic stopper 111 from the rear side. Then,the rear side stopper 135 is pressed forward by the head portion 72 b ofthe bolt 72 and thus the deformation portion 124 (holding portion 126)is pressed forward via the engagement claw 133. Therefore, thedeformation portion 124 is deformed to be spread with, for example, aboundary portion between the deformation portion 124 and the bottom wall116 as an origin.

As shown in FIG. 21, the telescopic stopper 111 rotates in the directionA2 with respect to the lock bolt 100, in accordance with deformation ofthe deformation portion 124. When the rear side stopper 135 movesforward and downward in accordance with rotation of the telescopicstopper 111 in the direction A2, the rear side stopper 135 is withdrawnfrom the head portion 72 b of the bolt 72 in a front view. Accordingly,the head portion 72 b of the bolt 72 passes through the telescopicstopper 111 (space between EA stoppers 112) and thus the inner column 22and the fixation member 71 further move forward.

As described above, in the present embodiment, the bolt 72 comes intocontact with the telescopic stopper 111 at the time of the collapsestroke. Therefore, the telescopic stopper 111 is withdrawn from the bolt72 of the fixation member 71.

According to this configuration, it is possible to suppress continuousinterference between the telescopic stopper 111 and the bolt 72 at thetime of the collapse stroke. Therefore, it is possible to suppress abumping load that is generated due to contact between the telescopicstopper 111 and the bolt 72 and to alleviate a variation in load at thetime of the collapse stroke. Accordingly, it is possible to efficientlyalleviate an impact load over the entire collapse stroke. As a result,it is possible to achieve an improvement in impact absorbingperformance.

Furthermore, in the present embodiment, the telescopic lock teeth 75 andthe EA elongated hole 64 overlap each other in the shaft axialdirection. Therefore, it is possible to reduce the length of the hangerbracket 51 in the shaft axial direction in comparison with a case wherea telescopic stroke region (telescopic lock teeth 75) and a collapsestroke region (EA elongated hole 64) are arranged in the shaft axialdirection, for example. Accordingly, it is possible to achieve reductionin size of the column unit 11 in the shaft axial direction.

In the present embodiment, the holder 110 that is engaged with the boltengagement portion 103 supports the telescopic stopper 111. With regardto this, the telescopic insertion hole 130 of the telescopic stopper 111is formed to have a diameter larger than the maximum outer diameter ofthe bolt engagement portion 103.

According to this configuration, the telescopic stopper 111 can rotatein accordance with rotation of the lock bolt 100 at the time of thetelescopic motion. The telescopic stopper 111 can rotate in a withdrawaldirection by coming into contact with the fixation member 71 at the timeof the collapse stroke.

In the present embodiment, the lock mechanism 53 is provided with theholder 110 that supports the telescopic stopper 111.

According to this configuration, it is possible to reliably cause thetelescopic stopper 111 (rear side stopper 135) and the fixation member71 (bolt 72) to come into contact with each other at the maximumcontraction position of the inner column 22 at the time of thetelescopic motion. Accordingly, it is possible to restrict the innercolumn 22 from moving forward with respect to the outer column 21.

Furthermore, at the time of the collapse stroke, the deformation portion124 of the holder 110 is deformed in accordance with rotation of thetelescopic stopper 111 when the bolt 72 comes into contact with thetelescopic stopper 111. Therefore, the telescopic stopper 111 cansmoothly rotate and it is possible to suppress a bumping load that isgenerated due to contact between the telescopic stopper 111 and the bolt72. As a result, it is possible to alleviate a variation in load at thetime of the collapse stroke.

Hereinabove, preferred examples of the present invention have beendescribed. However, the present invention is not limited to theexamples. Modifications such as addition, omission, substitution, andthe like of components can be made without departing from the spirit ofthe present invention. The present invention is not limited by the abovedescription and is only limited by appended claims.

For example, in the above-described embodiment, a configuration in whichthe axis O1 intersects the shaft axial direction has been described.However, the invention is not limited to this configuration. The axis O1may coincide with the shaft axial direction of the vehicle.

In the above-described embodiment, a case where the front sidetelescopic restricting portions 77 of the hanger bracket 51 and thefixation member 71 are adopted as telescopic restricting portions hasbeen described. However, the invention is not limited to thisconfiguration. For example, a telescopic restricting portion that movesalong with the inner column at the time of the collapse stroke may befixed to the inner column 22.

In the above-described embodiment, the bolt 72 is a hexagonal head bolt.However, the bolt 72 may be a round head bolt or a round head screw.

That is, any bolt can be adopted as long as the bolt 72 can come intosurface-contact with the bolt receiving portion 136 (as long as bolt 72do not come into point-contact with bolt receiving portion 136).

In the above-described embodiment, a configuration in which the innercolumn 22 is provided with the hanger bracket 51 such that the hangerbracket 51 faces the lower side has been described. However, theinvention is not limited to this configuration. For example, the innercolumn 22 may be provided with the hanger bracket 51 such that thehanger bracket 51 faces the upper side or a lateral side.

In the above-described embodiment, a configuration in which the entirecollapse stroke region overlaps the telescopic stroke region has beendescribed. However, the invention is not limited to this configurationas long as at least a portion of the collapse stroke region overlaps thetelescopic stroke region.

In the above-described embodiment, a configuration in which thetelescopic stopper 111 is held by the holder 110 has been described.However, the invention is not limited to this configuration.

In the above-described embodiment, the guide portions 33, the EA wire52, the top plate portion 61, and the like have been described as anexample of a sliding friction portion. However, the invention is notlimited to this configuration as long as a sliding friction portion isprovided with at least one of the guide portions 33, the EA wire 52, andthe top plate portion 61. A member other than the guide portions 33, theEA wire 52, and the top plate portion 61 may be used as a slidingfriction portion as long as the sliding friction portion slides on atleast one of the inner column 22 and the hanger bracket 51 at the timeof the collapse stroke. A coating material having a high frictionalcoefficient may be applied to each sliding portion.

In addition to above, a constituent element in the above-describedembodiment can be appropriately substituted with a known constituentelement without departing from the spirit of the invention and theabove-described modification example may be appropriately combined withthe embodiment.

What is claimed is:
 1. A steering device comprising: an outer columnthat extends in a front-rear direction and is formed with a slitextending in the front-rear direction; an inner column that is insertedinto the outer column such that the inner column moves in the front-reardirection and into which a steering shaft is inserted such that thesteering shaft rotates around a first axis extending in the front-reardirection; a switching unit that is provided with a lock bolt rotatingaround a second axis extending in a lateral direction and that isconfigured to switch between a locked state, in which the inner columnis restricted from moving with respect to the outer column, and anunlocked state, in which the inner column is allowed to move withrespect to the outer column, by expanding or contracting the slit; atelescopic restricting portion provided for the inner column; and atelescopic stopper that is engaged with the telescopic restrictingportion when the inner column moves in the front-rear direction withrespect to the outer column in the unlocked state such the inner columnis restricted from moving in the front-rear direction with respect tothe outer column, wherein a holder that is configured to rotate aroundthe second axis in accordance with rotation of the lock bolt isconnected to the lock bolt, wherein the telescopic stopper is held bythe holder to be supported by the lock bolt such that the telescopicstopper rotates around the second axis, and wherein, in a case where aload in a forward direction that acts on the inner column is equal to orgreater than a predetermined value in the locked state, the telescopicrestricting portion and the telescopic stopper come into contact witheach other such that the telescopic stopper rotates in a withdrawaldirection in which the telescopic stopper is withdrawn from thetelescopic restricting portion.
 2. The steering device according toclaim 1, wherein an outer circumferential surface of the lock bolt isformed with a bolt engagement portion, wherein the holder is providedwith a holder insertion hole that is engaged with the bolt engagementportion, and wherein the telescopic stopper is provided with atelescopic insertion hole of which a diameter is larger than a maximumouter diameter of the bolt engagement portion.
 3. The steering deviceaccording to claim 1, wherein the holder is configured to be deformedwith the telescopic stopper rotating in the withdrawal direction.
 4. Thesteering device according to claim 1, further comprising: an energyabsorbing (EA) stopper that is connected to the lock bolt and rotatesaround the second axis in accordance with rotation of the lock bolt; anda hanger bracket that is provided with a telescopic engagement portionwith which the EA stopper is engaged in accordance with rotation of thelock bolt and that is attached to the inner column via a fixationmember, wherein the hanger bracket and the fixation member constitutethe telescopic restricting portion, wherein, in the case where the loadin the forward direction that acts on the inner column is equal to orgreater than the predetermined value in the locked state, the EA stopperand the telescopic engagement portion are engaged with each other suchthat the inner column and the fixation member move forward with respectto the hanger bracket, wherein at least a portion of the hanger bracketin the front-rear direction that overlaps the telescopic engagementportion is formed with a guide hole that extends in the front-reardirection and guides movement of the fixation member with respect to thehanger bracket, and wherein the fixation member comes into contact withthe telescopic stopper in accordance with the movement of the innercolumn and the fixation member with respect to the hanger bracket. 5.The steering device according to claim 4, wherein the fixation memberand the telescopic stopper abut onto each other in a directionintersecting the front-rear direction in the unlocked state such thatthe inner column is restricted from moving forward.